IP multimedia services improvements in the GSM/EDGE radio access network

In the release 6 of the 3GPP standards, a new type of physical layer is being designed for the GSM/EDGE radio access network (GERAN): the flexible layer one (FLO). The main advantage of FLO is that configuration of the physical layer is done by the network at call setup. Consequently support of new services such as IP multimedia subsystem (IMS) services can be handled smoothly without having to specify new coding schemes in each release of the 3GPP specifications. Through several enhancements, FLO significantly improves the link level performance of real-time IMS services compared to GERAN release 5. Furthermore, the architecture of FLO brings GERAN even closer to UTRAN and together with Iu alignment, it enables seamless provision of 3G services over the two radio access technologies.